This invention generally relates to a wet disc brake cooling system and more particularly to a wet disc brake cooling system that is powered by the vehicle's axle shaft.
Heat builds up in wet disc brake systems due to the numerous frictional forces within the brake system. As heat builds up within the brake housing, the temperature of the brake fluid within the brake housing increases. The high temperature of the brake environment also increases the temperature of other vehicle components, namely the axle housing. There are several known systems used to reduce the temperature of the brake fluid, thus reducing the heat build up within the wet disc brake system.
One system involves forced cooling of the wet disc brake. Forced cooling requires cooling lines and an external pump that pumps brake fluid out of the brake housing, through the cooling lines and back into the brake housing. This system is strictly limited to drawing the brake fluid from the brake housing, cooling the fluid, and directing the fluid back to the brake housing. There are several disadvantages of this system. First, it is expensive because a separate part, the external pump, needs to be included in the system. Second, the additional part increases the overall weight of the vehicle. Third, the system only cools the brake environment. This system does not actively cool the axle housing environment.
Another system is a sump cooling system through the axle. In this type of system the fluid flows freely between the brake housing and the axle housing. The sump cooling system does not require any forced cooling lines. Rather, the brake fluid flows from an environment with an increased temperature, the brake housing, to a cooler environment, the axle housing. The disadvantage of the sump cooling system is that a high thermal cooling gradient develops between the brake and axle.